I've received many requests for help on this topic (How to use an external battery pack with a Tidalforce bike or how to fix my Tidalforce front hub battery), that I thought I would put it into one blog post versus the many that I have on the subject.
First off, you're probably reading this since you have recently come across a used Tidalforce electric bike or currently have a Tidalforce electric bike that has a front hub battery that is either dying or is completely dead! This is pretty common since Tidalforce (also known as Wavecrest Labs) went out of business in 2006 (or thereabouts) and getting replacement batteries is either very expensive or very difficult to do. Many folks give up and just sell their Tidalforce bikes in desperation. They probably loved the bike when it was running and totally enjoyed riding a smooth, quiet, powerful electric vehicle and hate giving up on it, however, there doesn't seem to be much hope for reviving the battery and so they sell their dying bikes for a song.
If you happened across one of these dying Tidalforce bikes, congratulations on your great buy and please read on!
If you've had your Tidalforce for a while and are looking to replace the battery, then please read on.
Let's start with the bad news!
You've probably thought of the possibility of replacing the bad cells inside the front hub and you're wondering if this is possible. The practical answer is no, unless you have lots of electronics experience and some specialized equipment. The special equipment you need is a battery analyzer, a tab welder, and some very high quality NiMH D cells. The battery analyzer is used to test the 30 (or more) NiMH D cells to match them for voltage and capacity. This is critical since any mismatched cells that are either high or low in voltage or capacity will not last long in the pack and any one bad D cell will determine the capacity and longevity of your entire pack. You'll need a tab welder as well to replace the D cells in your front hub. It is not practical to simply replace the defective D cells in your front hub. Any new cells that don't perfectly match your existing cells will guarantee that your rebuilt pack will not last long. The mismatch D cell will either discharge too much current or not enough current and die an early death.
There is also the matter of the technical skill to disassemble a very complex pack and to reassemble it after you've replaced the cells. This is not something that many people can do. Take a look at some of my other posts of my dead packs and you'll see that it is very complex and challenging.
Now, the good news!
All Tidalforce electric bikes, the M-750, M-750X, S-750, S-750X, iO and the iOX, are all capable of using external batteries. You will need a small jumper and some technical skills. Namely, knowledge of batteries and some basic electronics knowledge. Officially, the external battery when sold by Wavecrest Labs/Tidalforce was the "B Battery." The front hub battery was called the "A Battery."
You will need to work with some fairly heavy-duty batteries and delicate electronics circuits. Use caution!
Disconnect all connections from this console to any other component on your Tidalforce bike!
There are many connectors leading from this console to the front hub battery, the throttle, and the rear motor. Disconnect them all! That way, you reduce the risk of causing a short or other electrical issue with the system possibly live with electricity!
Let's get started!
After you've disconnected everything, take a look at the console or dashboard. It should look like this:
You will need to dismount this console by loosening or removing the screw holding it to the handlebars and open it up so that you can get access to the circuit inside.
Flip it over to see this:
Carefully look at this arrangement. You'll notice 5 screws, 5 wires and one white plastic insert in an unused wire slot. KEEP TRACK OF THIS PLASTIC INSERT! This insert helps to keep the console water resistant. Without it, water can easily enter and short out your bike! You've been warned!
Now that you have it open, you'll see clusters of wires and flexible cable inside. Ignore all of these. We are looking for one particular set of jumpers inside.
Here's the circuit board without any wiring to show you what jumpers you're looking for. First, look for the block called "Batt2". I have outlined it in red below. After you spot the block, then look for the second set of jumpers close to the "Batt1" connector. I've outlined it with two red lines below.
You will need to jumper those two pins on the circuit board. It's called the "B Battery Jumper."
In order to create this jumper, you can either improvise by looking for a small jumper from your junk PC or hard drive, or create one from the official parts available at places like Mouser.com or Digikey.com.
This is the correct jumper block for the "B Battery" connector on the console.
The description on the order form is a bit cryptic.
"H2006-ND .49600 4.96 T
CONN 2MM HOUSING 14 POS DUAL
HTSUS: 8536.69.4050 ECCN: EAR99
LEAD: LEAD FREE ROHS: ROHS COMP
The sockets which go inside this housing are these:
"H9999-ND .18200 3.64 T
CRIMP TERMINAL A3B-A4B TYPE
HTSUS: 8538.90.8040 ECCN: EAR99
LEAD: LEAD FREE ROHS: ROHS COMP
These are very tiny parts and require great skill in order create.
You will also need some very fine gauge wire in order to jumper across these two pins. 22 or 24 gauge should do the trick. The jumper does not carry any significant current as far as I can tell. It's just a signal wire. It's either present or not.
To show you how small this connector pin is, see the picture here:
That's the pin in the palm of my hand!
To help with crimping this tiny pin, I bought this $9 crimper from my local Radio Shack:
It's officially called a "D-Sub Pin Crimper".
Lastly, here's a completed jumper.
Now, insert this little header block you've just created onto the "Batt1" connector in the console. This is what it should look like.
Make certain that you've got a good connection with the connector and that it's solid in the socket, reassemble the back cover of the console and be sure that no wires are crimped and that the little white plug is in place!
Now that you've enabled the B battery option on the console on your Tidalforce bike, it's time to configure an external battery for your newly em"power"ed Tidalforce! Please check out my next post!